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WIP World of Calen Ndor

In an attempt to learn more of the techniques here in the hope that will help me develop my own style i have just about got something ready to post after quite a bit of planning.

My main interest is getting a realistic layout for my maps based on fairly accurate geology and climate models so I'm going to create a world from scratch, follow the steps below and then pick particular continents/island/region and map them in more detail in a particular style depending on the tutorial I'm following at the time.

The world is called Calen Ndor which in my best pidgin Tolkien means "Green Land". Thanks for reading and if you spot any mistakes or have any pointers they will be gratefully received.

I picked one a jagged section of plates to run the whole length of the world moving apart. at the opposite boundary i had the plates coming together.

The Green lines are where plates are spreading apart at constructive (divergent) plate margins and the blue lines at destructive (convergent) margins. The unmarked lines will either be transform faults or inactive.

The next stage was a lot of trial and error creating a new layer and just sketching with a large soft green brush to get the land areas in the right places. to give a balance of land and sea.

I wanted the land to cross the plate margins because that gives the more interesting features. I had in mind (very generally):
constructive margins at sea create mid ocean ridges
constructive margins on land create rift valleys

I used the very rough island outlines and RobA's Making Not So Random Coastlines in GIMP in Photoshop to create a more realistic coastline. It was absolutely perfect for the island chains, i selected each one in turn with a lasso tool and used the threshold adjustment to get them nice and broken up.

The main island shapes need a bit of work but that will vary depending on river paths, mountains, deltas and ocean currents so they can stay as are for the time being. The island chains I'm very pleased with.

This gave me a slightly tidier version of my last map. Dark green will be mountains and light green rift valleys.

To go onto the next section i needed to add the important latitude lines. From a climate point of view these are the equator (0), 30 and 60 degrees rather than the 23 and 66 degrees usually marked on a map (tropic of Capricorn, Cancer, the Arctic and Antarctic circles).

I'm going to ignore any axial tilt (which produces the seasons). these can be added later when needed to add spice to an individual map. Instead I'm going to assume all incoming solar radiation is equal. This is obviously greater at the equator at less towards the poles. This means ignoring all other factors the temperature map of Calen Ndor looks as below:

The next stage gets into Atmospheric circulation and therefore much more complicated so I'm going back to my text books!

The heat concentrated heat at the equator means hot air rises and sinks at the 30 degree mark, this is called the Hadley Cell.

The Polar Cell carries the (relatively) warm and moist air from the 60 degree region to the poles where is sinks as it cools.

The final mixing zone between 30 and 60 degrees is more complicated. The Ferrel Cell relies on the air movements on the two other cells rather than solar radiation and as a result the weather here is much more unstable (as anyone British should be familiar with!).

This means the worlds air pressure maps looks as follows:

This air pressure is very important to the map because it will influence the wind directions on the map and the rainfall.

Winds travels from high pressure areas to low pressure areas. Coriolis Force means winds in the northern hemisphere bend to the right and to the left in the southern hemisphere. This means the predominant air flows of the world are:

Even more important are the effects of pressure on rainfall. In very general (and simplified terms) low pressure areas have higher rainfall because the air is cooling and sinking. In high pressure areas the air is rising and generally rainfall is lower. The exception to the rule is the Equator where the air converges from the north and south and is characterized by heavy rainfall.

Looking at a World Climate Map you can see the 30 degree latitudes contain the worlds major deserts.

So for my world the following maps shows the wet and arid areas:

All of the information so far hasn't been affected by any of my map features. The next stage is to add the effect of mountain ranges on atmospheric circulation and therefore rainfall and try to add simple ocean currents that will add a bit of randomness to the (eventual) climate type.

The next task is to add the effect of the major mountain chains on rainfall. As the wind blows and encounters a mountain range it rises cools and any moisture falls as rain. on the other side of the mountains a rain shadow forms because all of the moisture from the air has already fallen.

So using the prevailing wind directions shown previously the rainfall map can be modified to show areas that would be drier than expected and wetter than expected (the black lines represent the mountain chains):

Next stage is ocean currents. A bit of a dark art this one so I'm going to stick with the basic rules and fly by the seat of my pants. Been a while since i did any oceanography so if anyone in the know sees any glaring errors please let me know.

The first rule is warm water flows from the equator to the poles and vice versa. The ocean currents are affected by Coriolis Force and so bend to the right in the northern hemisphere and to the left in the south. Obviously the shape of the land will affect flow so using these basic rules my worlds ocean currents look as below:

Ocean currents are very important at distributing heat so i can modify the earlier heat map as the ocean currents shown above carry warm water to the poles and as cold water returns. This gives an ocean temperature map as below:

Although its unlikely a fantasy map will never show ocean temperature this is very important on later land types. For example the warm ocean current flowing past the northern island arc means they will be much warmer than the latitude itself would suggest. The ocean also acts as a thermal blanket keeping costal areas milder while inland regions cool much faster. So using this and the ocean temperatures i have spread the effects onto the land to give the land average land temperature map:

Just for the sakes of a pretty map i combined the two temperature maps:

So now we have all the essential data i need to do the map. The next stage is producing a climate map showing how the tundra, desert, rain forest etc will be positioned.

Bravo, bravo. I love the step-by-step logical world-building approach. I attempted to do this on my own map, but my own understanding of these facts was much to feeble to reach quite the level you are going to. In particular, I missed the consideration of how oceanic currents affect overall climate and temperature.

You're efforts are certainly commendable!

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Pimping my worldmap here. Still WIP... long way to go, but I'm pretty proud of what I've done so far...

C - In Humid Middle Latitude Climates land/water differences play a large part. These climates have warm,dry summers and cool, wet winters.

D - Continental Climates can be found in the interior regions of large land masses. Total precipitation is not very high and seasonal temperatures vary widely.

E - Cold Climates describe this climate type perfectly. These climates are part of areas where permanent ice and tundra are always present. Only about four months of the year have above freezing temperatures.

Of course these are very basic but allow me to map the background terrain of any area and then add in local climate effects and human influence more realistically.

The next stage is to actually try and make some pretty maps, but I'm happy that unlike all the previous maps i have tried to make i won't have to spend hours worrying about what the air and ocean currents, latitude and prevailing wind are doing.

I have a had a little bit of time to start on one of the maps in more detail. I'm choosing the centre southern continent. It is about 550 miles East to West and 400 miles North to South making it similar in size to France.

As you can see from the previous map the northern area is desert similar to North Africa and then down to A Scandinavian climate in the South. The range of temperatures is large because my southern area doesn't have the Gulf Stream equivalent keeping it artificially warmer. So far i have only added the drainage pattern. I have put quite a bit of thought into this:

The higher the number of rivers is obviously related to the amount of rain in the area. The shape of the rivers is related the the hills and mountains in the area (which will be clearer when i add them!)

Next stage is to add the mountains but I'm still deciding on the style of map to try.